You might describe a chair that is big enough to comfortably seat an entire family rather than just one person as Brobdingnagian due to its unusually large size.
Brobdingnagian is a term that describes anything enormous in size. The word comes from Jonathan Swift's novel Gulliver's Travels, where Brobdingnag is a fictional land inhabited by giants. When we say something is Brobdingnagian, we mean it’s extraordinarily large or colossal. For example, a Brobdingnagian pizza would be so big that it barely fits through the door! The opposite of Brobdingnagian is Lilliputian, which comes from the same novel, and describes things that are very small.